Systems and methods for determining magnetic location of wireless tools

Abstract

A method for locating a tool in a 3D space is provided. The method includes determining whether location data, corresponding to a location of the tool, is available. If the location data is available, the method includes providing the location data for presenting the location of the tool. If the location data is not available, the method includes determining an estimated location of the tool based on a velocity of the tool and an acceleration of the tool, generating estimated location data corresponding to the estimated location of the tool and providing the estimated location data for presenting the estimated location as the location of the tool. The method also includes determining whether accelerometer data is available. If accelerometer data is available, the method includes using the accelerometer data to estimate the location of the tool.

What is claimed is: 
     
       1. A method for locating a medical tool in a three dimensional (3D) space within a heart during a surgical procedure using an electromagnetic navigation system, the method comprising:
 receiving transmitting signals from one or more sensors of the medical tool, the one or more sensors comprising at least a magnetic field location sensor disposed at a tip of the medical tool, the magnetic field location sensor provides an amplitude and a phase of magnetic fields within the heart within the transmitting signals, the magnetic fields being generated by one or more magnetic field generators external to the heart, and the amplitude and the phase indicating a strength of the magnetic fields being detected by the magnetic field location sensor; 
 determining whether location data, corresponding to a location of the medical tool, is available; 
 if the location data is available within the transmitting signals:
 controlling a display of the location of the medical tool based on the location data; and 
 providing anatomical information comprising maps of the heart in the display based on the location data; and 
 
 if the location data is not available within the transmitting signals:
 determining an estimated location of the medical tool based on the transmitting signals comprising a velocity of the medical tool and an acceleration of the medical tool in accordance with the strength of the magnetic fields; 
 continually generating estimated location data corresponding to the estimated location of the medical tool over time at equal intervals based on the velocity and the acceleration of the medical tool; 
 controlling the display of the location of the medical tool based on the estimated location data; and 
 providing in the display for presentation the estimated location data, the anatomical information comprising the maps of the heart based on the estimated location data, and the location of the medical tool. 
 
 
     
     
       2. The method of  claim 1 , further comprising:
 receiving an indication of the location of the medical tool; and 
 generating the indication of the location of the medical tool. 
 
     
     
       3. The method of  claim 1 , wherein if the location data is not available,
 determining whether accelerometer data, which indicates the acceleration of the medical tool, is available; and 
 if the accelerometer data is available, determining the estimated location of the medical tool based on the accelerometer data. 
 
     
     
       4. The method of  claim 1 , further comprising:
 calculating the velocity of the medical tool and the acceleration of the medical tool for a plurality of locations over time, and 
 determining whether accelerometer data, which indicates the acceleration of the medical tool, is available; and 
 if the accelerometer data is not available, determining the estimated location of the medical tool using one or more previous velocity calculations and one or more previous acceleration calculations of the medical tool. 
 
     
     
       5. The method of  claim 4 , wherein:
 the one or more previous velocity calculations comprise calculating the velocity of the medical tool based on a change in location and a change in time; and 
 the one or more previous acceleration calculations comprise calculating the acceleration based on a change in the velocity and a change in time. 
 
     
     
       6. The method of  claim 1 , wherein the estimated location of the medical tool is determined remote from the medical tool. 
     
     
       7. The method of  claim 1 , wherein the estimated location of the medical tool is determined local to the medical tool. 
     
     
       8. The method of  claim 1 , wherein if the location data is not available:
 filtering, via a Kalman filter, the estimated location data to provide filtered estimated location data; and 
 providing the filtered estimated location data for presenting the estimated location of the medical tool. 
 
     
     
       9. The method of  claim 1 , wherein the magnetic field location sensor comprises one or more receiving coils oriented along different axes and the one or more magnetic field generators comprise one or more emitter coils. 
     
     
       10. The method of  claim 1 , wherein the location data include points in 3-D space, the strength of the magnetic fields, and a time stamp. 
     
     
       11. The method of  claim 1 , wherein the estimated location data is obtained from a relative velocity and acceleration based on a time when one or more velocities and accelerations are calculated relative to a current estimation. 
     
     
       12. The method of  claim 1 , wherein the method further comprises:
 calculating the velocity of the medical tool includes using location and time changes to calculate first and second velocities; 
 calculating the acceleration of the medical tool using the first and second velocities; and 
 determining the estimated location of the medical tool is based on calculating using a sum of a previous location, the velocity, and the acceleration. 
 
     
     
       13. The method of  claim 1 , wherein the velocity and acceleration of the medical tool are calculated for a plurality of locations over time, and wherein the equal intervals comprise five (5) millisecond intervals. 
     
     
       14. An electromagnetic navigation system for locating a medical tool in a three dimensional (3D) space within a heart during a surgical procedure, the electromagnetic navigation system comprising:
 a memory configured to store data; and 
 a processor, in communication with the memory, configured to:
 receive transmitting signals from one or more sensors of the medical tool, the one or more sensors comprising at least a magnetic field location sensor disposed at a tip of the medical tool, the magnetic field location sensor provides an amplitude and a phase of magnetic fields within the heart within the transmitting signals, the magnetic fields being generated by one or more magnetic field generators external to the heart, and the amplitude and the phase indicating a strength of the magnetic fields being detected by the magnetic field location sensor; 
 determine whether location data, corresponding to a location of the medical tool, is available; 
 if the location data is available within the transmitting signals;
 control a display of the location of the medical tool based on the location data; and 
 provide anatomical information comprising maps of the heart in the display based on the location data; and 
 
 if the location data is not available within the transmitting signals:
 determine an estimated location of the medical tool based on the transmitting signals comprising a velocity of the medical tool and an acceleration of the medical tool in accordance with the strength of the magnetic fields; 
 continually generate estimated location data corresponding to the estimated location of the medical tool over time at equal intervals based on the velocity and the acceleration of the medical tool; 
 control the display of the location of the medical tool based on the estimated location data; and 
 provide in the display for presentation the estimated location data, the anatomical information comprising the maps of the heart based on the estimated location data, and the location of the medical tool. 
 
 
 
     
     
       15. The electromagnetic navigation system of  claim 14 , wherein the processor is further configured to:
 receive electrical signals indicating a plurality of locations of the medical tool over time; and 
 generate the location data based on the electrical signals. 
 
     
     
       16. The electromagnetic navigation system of  claim 14 , wherein if the location data is not available, the processor is further configured to determine whether accelerometer data, which indicates the acceleration of the medical tool, is available; and
 if the accelerometer data is available, the processor is further configured to determine the estimated location of the medical tool based on the velocity of the medical tool and the accelerometer data. 
 
     
     
       17. The electromagnetic navigation system of  claim 14 , wherein the velocity and acceleration of the medical tool are calculated, over time, for each of a plurality of locations, and
 the processor is further configured to determine whether accelerometer data, which indicates the acceleration of the medical tool, is available; and 
 if the accelerometer data is not available, the processor is further configured to determine the estimated location of the medical tool by using one or more previous velocity calculations and one or more previous acceleration calculations of the medical tool. 
 
     
     
       18. The electromagnetic navigation system of  claim 14 , wherein if the location data is not available:
 filtering, via a Kalman filter, the estimated location data to provide filtered estimated location data; and 
 providing the filtered estimated location data for presenting the estimated location of the medical tool. 
 
     
     
       19. A non-transitory computer readable medium having instructions locating a medical tool in a three dimensional (3D) space within a heart during a surgical procedure using an electromagnetic navigation system, the instructions executable by a computer of the electromagnetic navigation system to cause the electromagnetic navigation system to perform:
 receiving transmitting signals from one or more sensors of the medical tool, the one or more sensors comprising at least a magnetic field location sensor disposed at a tip of the medical tool, the magnetic field location sensor provides an amplitude and a phase of magnetic fields within the heart within the transmitting signals, the magnetic fields being generated by one or more magnetic field generators external to the heart, and the amplitude and the phase indicating a strength of the magnetic fields being detected by the magnetic field location sensor; 
 receiving electrical signals indicating the location of the medical tool; 
 generating location data based on the electrical signals; 
 determining whether the location data, corresponding to a location of the medical tool, is available and whether accelerometer data, which indicates an acceleration of the medical tool, is available; 
 if the location data is available within the transmitting signals:
 controlling a display of the location of the medical tool based on the location data; and 
 providing anatomical information comprising maps of the heart in the display based on the location data; and 
 
 if the location data is not available within the transmitting signals:
 continually determining estimated location data over time at equal intervals, corresponding to an estimated location of the medical tool based on the transmitting signals comprising a velocity of the medical tool and the acceleration of the medical tool in accordance with the strength of the magnetic fields, the velocity and acceleration of the medical tool are calculated for a plurality of locations over time; 
 controlling the display of the location of the medical tool based on the estimated location data; and 
 providing in the display for presentation the estimated location data, the anatomical information comprising the maps of the heart based on the estimated location data, and the location of the medical tool. 
 
 
     
     
       20. The non-transitory computer readable medium according to  claim 19 , wherein the instructions are executable to cause the electromagnetic navigation system to perform:
 if the accelerometer data is available, determining the estimated location of the medical tool based on the velocity of the medical tool and the accelerometer data; and 
 if the accelerometer data is not available, determining the estimated location of the medical tool further comprises determining a current estimated location of the medical tool using one or more previous velocity and acceleration calculations of the medical tool at one or more previous locations.